<style type="text/css">
	#editor1 { position: relative; }
	.misplaced { position: absolute; width: 50px; height: 50px; outline: 2px solid black; }
	#reference { text-align: center; outline-color: blue; }
</style>

<div id="editor1">
	<div class="misplaced" id="center"></div>
	<div class="misplaced" id="reference">
		<p>This is your reference viewport.</p>
	</div>
</div>